Such an estimation algorithm of a frequency error relating to a received symbol based on a phase sequence is described, for example, in paragraph 4.1 (page 107) of the article <<Feedforward Frequency Estimation for PSK: a Tutorial Review>>by M. Morelli and U. Mengali, published in the journal <<European Transactions on Telecommunications, vol. 9, no. 2, March-April 1998>>. This algorithm is known by the name of Tretter algorithm, or least squares method.
To obtain such a phase sequence, it is known that a phase estimation algorithm is used, which estimates the phase relating to a received symbol on the basis of decisions made on various received symbols. For example, the expectation maximization algorithm is used, which is described in paragraph 3.3 of the conference report of the <<International Conference on Communications, New Orleans, USA, 1-5 May, 1994, vol. 2, pp. 940 and 945>>, entitled <<Comparison between digital recovery techniques in the presence of frequency shift>>by F. Daffara and J. Lamour.
The problem posed is the following: in a PSK modulation comprising 2n points, two adjacent points have a phase difference of
      π          2              n        -        1              .When the frequency error is such that, based on a certain symbol, an error is made in the decision, this error is translated by a phase jump of
  ±          ⁢      π          2              n        -        1            in the sequence of phase estimates obtained. The number of phase jumps that may be obtained depends on the number of symbols contained in the packet and the initial frequency difference.
When the sequence of phases, which are used for applying the Tretter algorithm, includes one or various phase jumps, the frequency estimate obtained is inaccurate. The invention notably has for its object to provide a solution to this problem.